Templet etching device



1952 R. x. LOWNDES, JR 2, 78

TEMPLET ETCHING DEVICE Filed April 11 1950 2 SHEETS-SHEET l km/Pr/W Jan. 29, 1952 R E JR 2,583,578

TEMPLET ETCHING DEVICE Filed April 11, 1950 2 SHEETS SHEET 2 will! R.I.LOWNDE$, mv

Patented Jan. 29, 1952 UNITED STATES P TENT OFFICE 6 Claims.

The invention herein described may be manufactured and used by or for the Government of the United States of America for governmental purposes throughout the world, without the payment to me of any royalty thereon.

This invention relates to an apparatus for transferring radial lines from aerial photos, or other pictures, to a Celluloid or other transparent or translucent template.

An object of this invention is to avoid or minirinse the errors in photogrammetric mapping which arise in the step of extending a radial line through a picturepoint 'to a template.

A very slight variation or error in the placing of a straight edge coincident with the picture center and the selected picture point causes a large error in the location of the radial line etched on the template. Variations in the slope of this needle used to scratch the template, in

the straightness of the straight edge, and in unfastening means for the slotted bar or st'raight edge, viewed in the direction of line 5-5 of Figure 4;

Figure 6 is a sectional detail of the etc-hing needle unit mounted on thesli'de;

Figure '7 is a view of the other end of the slotted bar.

The apparatus comprises a ground glass disc I seated on the flange 2 of a frame 3, and fastened in place by ring or gasket "4'. Frame 3 mounted upon a stationary hollow standard 5 which is rigidly fastened in tripod 6 by "nut 1, round on threaded end 50 of the standard. Yoke 8 is rotatably mounted upon the standard by housing 8|), being supported by a flange 9 attached to the standard. electrical conductor (not shown) for the lamps Ill may be inserted through the hollow standard 5.

The slotted bar H is fixedly attached at the right end (Figure 4) to the yoke 8 by means of a screw and nut unit 12. consequentl bar it amended April 30, 1928; 370 0; G. 757) I z and yoke s can be rotated together through any angle about the axis of standard 5.

A clamp comprising jaws 13, which pivot on pin I36, seizes the holding flange M of theframe 3 when thumb screw [5 is turned; One such clamp is shown mounted upon the yoke 8, at the right end; One mode of mounting the clamp is shown in Figure 5'. Pivot pin I3?! is attached to and is an extension of pin [6 Pin It; is slidably mounted in sleeve l Si] in saddle I! of yoke 3.

A compression spring [8 is seated about It between right flange 20, of the pivot I30. and the sleeve Hit. It pushes against the flange" 20 and against the sleeve it!) when compressed; When thumbscrew i9 is turned a to apply pressure against the left flange 20, also attached to pivot ass, it causes saddle I1, and yoke 8, to compress the spring and move to the left, in Figure 5, provided that clamp jaws I; have previously been tightened upon and hold flange i4. Consequently, thumbscrew I9 is a fine adjustment screw. Thumbscrew l5 isthe initial coarse adjustment screw. g

The left end of the bar I I (Figure 7) is adjustably secured'to the yoke 8 by bolt 21 and nut 28 in slot 29. Two adjusting screws 30*a'nd 3| are provided to adjust theleft end laterally.

The carriage or slide 2| has a spring 22 to hold the opposite edge tightly against the corresponding edge of the bar II. The edges of carriage 2| slide in straight edge slots 23 in bar H. Bar II has a longitudinal depression 24 in which is placed scale 25 representing the scale of the picture and a scale 28 representing the scale to which the template is to be etched. The bronze straight edge or bar I I is parallel to a great chord of the glass disc I and about one fourth of an inch to the side of it. The telescope 32 is provided with a cross-hair 320. The telescope and the etching needle 34 are mounted so that the center of the cross-hair 320 and the needle point 34 are on a line parallel to the straight edge of II and directed precisely through the center 33 of the ground glass disc I. Needle 3'4 is vertical and is mounted for accurate vertical downward movement by"means of needle guide sleeve 369 and piston flange 340 slid'ably fitting in the chamber 330. V

The telescope or magnifier 32 and the etching needle unit 33 are mounted uponth'e slide 2i. Ordinarily the needle 34 is retracted upwardly by the spring 35, being pushed down into "etching position by pressing button 36.

The ground glass plate I is provided with a reotangulardepr'essien '31 to receive and position the aerial photo. To accurately position the photo a number of other expedients are employed. The pin point 38 projects from the center of the depression. This pin point is designed to pass through a corresponding pin hole in the picture center of the aerial photo (not shown), and of the transparent template (not shown).

The ground glass plate is provided with four short glass columns or rods 39 about one quarter inch in diameter (Figure 1) and non-symmetrically positioned adjacent the corners of the depression. The bases of the columns should be slightly smaller than the tops. The aerial photo is provided with correspondingly non-symmetrically placed holes to receive the rods. Consequently the aerial photo can be placed upon the glass plate in one position only, and accurately so. Lines 4;] running toward the point 38 from the middle of the sides, and the designation mark N etched on the glass plate, assist in the placement. 7

For additional convenience, the slide is provided with a pointer 2H! for the telescope and a pointer III for the etching needle. The telescope scale at 25 has its'zero origin at the center of the glass disc. The needle scale at 25 has its origin at a point a distance to the right of the center equal to the distance between the cross-hair of the telescope and the etching needle point.

The replaceable needle point 36 is at the exact center of the glass disc. The point 38 projects through the center of the picture and of the translucent template (not shown). Need1e'38 is long enough to go through the picture and the template, but is not high enough to strike scoring needle 34 when it is not depressed.

In order to insure that the picture fits into the depression and over the columns, a special four-point punch is used to punch the picture, the punches of which should be about two onethousandths of an inch smaller than the glass columns. This punch should be equipped with a center needle point Over which the center oi the picture is placed, before punching, and held fiat by spring clips placed over each quarter point of the picture throughout its width.

When the picture is placed in the depression on the disk and over the glass columns, which fit tight enough to hold it in place, the center needle will, of necessity, come through the original hole at the pictures center and the north edge of the picture will always fall against the radial etched line marked with an N.

When the template is first put on, its center is pre-punched so that it too can be placed on the needle point extendingfrom the glass disk. Next the template should be squared with the cross radial lines as nearly as possible by eye and each corner held fast by the use or" Scotch tape.

The first lines cut on the template should be the outer one inch of the notch or etched lines and the north edge so marked. Next the flight lines can be out after which as many radial lines as desired. Naturally, all lines cut on the template will be done with the carriage needle after the straight edge has been placed by the use of the telescope, clamp and slow motion screws.

With the slow motion screw, clamp and magnified point, anyone should be able to place the cross-hair on the exact center ver quickly, then, without reaching for an additional tool, all he need do is to'slide the carriage forward, squeeze the f nger grip, and slide the carriage 4 a little further thus scoring the template exactly on the radial line. By using the scales, only one-eighth to one-quarter inch long score need be made, which will tend to keep the template from being cluttered up with lines, making it more workable.

Having thus described my invention, I claim:

1. An apparatus for transferring radial lines from a translucent map to a translucent template comprising: a translucent plate having a flat surface for receiving the map and the template above the map; a frame for fixedly mounting the translucent plate; a bar mounted for rotation in a plane parallel to the plate; means for so mounting the bar comprising a rotatable yoke; the bar having a straight edge; a sliding carriage mounted by the bar and guided by the straight edge; a magnifying sighting tube, having asighting mark, and an etching needle unit both mounted upon the carriage; the point of the needle and the sighting tube mark being in a line parallel to the straight edge; the frame having a circumferential rim; a clamp having jaws pivotedly mounted upon the yoke in position to seize the rim, a pivot mounting for said jaws being laterally displaceable with respect to the yoke; adjusting means having a surface adapted to be brought to position to bear force against the clamp mounting to displace the yoke laterally, about its axis of rotation, with respect to the clamp, when the clamp is previously fixed in. position; means for depressing and guiding the needle into template etching position in a line at a right angle to the fiat surface of the translucent Plate.

2. The apparatus of claim 1 in which the translucent plate is provided with a fiat depressed area to receive the map and the template; the depressed area being provided with eccentrically placed rodsadjacent the periphcry of the area, adapted to fit like placed apertures in the map, and a pin point projecting upwardly from the area and in substantial alignment with the axis of rotation of the bar,

adapted to fit into an aperture in the map and in the template.

3. The apparatus of claim 1 in which the pivot mounting of the clamp comprises a pin slidably supported in the yoke, spring means in operative position between the yoke and the pivot pin to be compressed upon displacement of the yoke with respect to the pin caused by operation of the adjustment means as recited.

4. An apparatus for transferring radial lines from a translucent aerial map, having a picture center, to a translucent template, comprising: a translucent plate having a fiat surface for receiving the map, and the template above the map; means fixedly mounting the plate; a bar, means for supporting the bar at its ends, the supporting means being rotatable about the periphery of the translucent plate and about an axis perpendicular to the plate; means for fastening the supporting means and bar against rotation with respect to the plate mounting means;- the bar having a straight edge; a sliding carriage mounted by the bar and guided by the straight edge; a magnifying sighting tube, having a sighting mark, and an etching needle unit both mounted upon the carriage; the point of the needle and the sight mark being in a line which is parallel to the straight edge and passing through saidaxis; means for depressing and guiding the needle into template etching position in a line at a right angle to the fiat surface of tne,translucent plate; the translucent plate having means projecting upwardly therefrom adapted to align the aerial map to accurately position the picture center of the map with respect to the axis of rotation of the bar. 5. An apparatus for transferring radial lines from a translucent map to a translucent template comprising: a translucent plate having a flat surface for receiving the map and the template above the map; a frame for fixedly mounting the translucent plate, comprising a housing under the plate, the housing containing means to illuminate the map and template; a bar mounted for rotation in a plane above and parallel to the plate; means for so mounting the bar comprising a yoke rotatable about the housing about a vertical axis; the bar having a straight edge; a sliding carriage mounted by the bar and guided by the straight edge; a magnifying sighting tube, having a sighting mark. and an etching needle unit both mounted upon the carriage; the point of the needle and the sighting tube mark being in a line whichis parallel to the straight edge and which passes through the axis of rotation of the yoke; means for depressing and guiding the needle into template etching position in a line at a right angle to the fiat surface of the translucent plate, and means for fastening the yoke to the frame.

6. The apparatus of claim 5 in which the translucent plate is provided with a flat depressed area to receive the map and the template; the depressed area being provided with eccentrically placed rods adjacent the periphery of the area, adapted to fit like placed apertures in the map, and a pin point projecting upwardly from the area and in substantial alignment with the axis of rotation of the bar, adapted to fit into an aperture in the map and in the template.

RICHARD I. LOWNDES, JR.

7 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,266,010 Golden May 14, 1918 1,424,941 Pirwitz Aug. 8, 1922 1,887,288 Clausen Nov. 8, 1932 1,927,992 Pulver Sept. 26, 1933 2,198,757 Bohrn et a1. Apr. 30, 1940 2,312,154 Fischer Feb. 23, 1943 FOREIGN PATENTS Number Country Date 86,865 Switzerland Mar. 16, 1921 

